Complete the Joda-style fractional-second and time-zone pattern support in libbeat/common/dtfmt .

Complete the Joda-style fractional-second and time-zone pattern support in libbeat/common/dtfmt .: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). An unquoted run of one through nine S characters must emit exactly that many leading decimal digits from the…